The present invention relates to passenger evacuation arrangements for aircraft safety, and in particular to a chute and associated deployment structures for evacuation of passengers from an upper deck of an aircraft in the event of an emergency.
Modern aircraft design, and in particular the proposed introduction of multi-deck aircraft into the fleet of commercial passenger aircraft, has given rise to novel safety concerns. In particular, rapid evacuation of passengers from the upper deck of an aircraft in the event of an emergency can pose problems. Conventional aircraft design calls for evacuation slides that may be deployed from an aircraft hatch. However, this arrangement is not well suited for use with an aircraft having two or more passenger decks, in which the upper deck is at a significant remove from the base of the aircraft fuselage. In particular, conventional inflatable aircraft slides do not typically possess the rigidity to accommodate a large lateral displacement between the top and bottom of the slide. Thus, such slides cannot readily accommodate the drop from the upper deck of a double deck aircraft. For this application (and others) there exists a need for alternative arrangements for evacuating passengers that are readily adaptable to applications involving lengthy drops.
It is proposed herein to apply certain of the principles and teachings of marine vessel evacuation arrangements for use in aircraft.
It is known within marine vessels to provide an emergency passenger evacuation arrangement that comprises an elongate fabric tubular member that may be suspended from an upper deck of the vessel. Typically, a framework is fixed to the vessel deck to support the chute. The interior of the tube or chute incorporates a means for slowing the rate of descent of passengers within the tube. With such an arrangement, passengers enter the tube from an upper deck of the vessel, and descend through the tube onto a waiting life raft or the like. Such an arrangement offers the advantage of being able to carry passengers in safety down a long descent. Further, the tube may be retained in a folded or bunched form within a relatively compact housing when not in use, and thus this arrangement represents when stowed a light weight and compact arrangement. Further, such a tube may be provided in virtually any length. Since the tube is suspended vertically rather than angled, structural rigidity is not required.
Examples of conventional marine evacuation passenger chutes may be found within the following references:
U.K. Patent Application No. 2,168,008 (Koizumi)
U.K. Patent No. 1,490,855 (Fujikura Rubber Works Limited)
U.S. Pat. No. 4,605,095 (Koizumi)
Conventionally, a marine chute deployment arrangement comprises a frame or the like fixedly mounted to a deck of a vessel, a portion of which overhangs the edge of the vessel to suspend the chute in a position somewhat displaced from the side of the vessel. The overhanging portion may either permanently overhang the vessel gunnel or be moveable between a fully inboard position and an overboard position upon deployment of the chute. A chute fabricated from fabric or other flexible material is housed in a folded or bunched form within a container associated with the frame, when in the stowed position. One end of the chute is fastened by cords or the like to the frame. Upon deployment of the chute, the chute is removed from the container and lowered or dropped over the side of the vessel, with the chute remaining attached and suspended at its upper end from the frame.
Within the chute, the rate of descent of passengers through the chute is controlled by various means. Typically, the chute comprises inner and outer fabric layers, with the inner chute layer forming a tortuous zig-zag path for effectively slowing the rate of descent of passengers within the chute. Alternatively, the inner chute layer may be partly elasticized, or other constriction means may be employed to create friction between the body of the user and the chute material.
In another aspect, an inflatable passenger platform may be associated with the base of the chute to receive descending passengers and provide a waiting area for the arrival of rescue craft. Further, various tensioning means permit users to properly tension the chute following deployment.
Within one aspect of the present invention, it is proposed to employ a generally conventional marine-type evacuation chute, in association with a frame and housing specifically adapted for aircraft use, in order to provide an emergency aircraft evacuation arrangement. The foldable chute may be conveniently stowed in an appropriate housing when not in use, and a frame specifically adapted for aircraft use suspends the chute over the side of an aircraft adjacent an escape hatch. It is noted that within conventional marine chute evacuation arrangements, the structure that suspends the chute over the side of the vessel is typically relatively large and is permanently fixed to the deck of the vessel adjacent the gunnel for rapid deployment of the chute. Such an arrangement is generally suitable for marine use. However, within the small confines of an aircraft, it is essential that a more compact deployment arrangement be provided, and it is further desirable to provide an arrangement whereby the frame may be positioned at some remove from the hatch when not in use, in order to provide free access to the hatch for entering and exiting passengers during normal aircraft operation. As well, it is of course essential that the chute deployment structure be capable of being housed entirely inboard of the aircraft when not in use and only extend outwardly from the aircraft when deployed.
In another aspect, the invention addresses the need during emergency evacuation of aircraft for particularly rapid passenger evacuation protocols. Thus, it is desirable to provide a rapid means for discharging passengers. One drawback of a marine type chute extending the full drop from an upper airplane deck is the time required for passengers to slide through such a tube. Thus it is desirable that at least a portion of the chute be replaced with a more expeditious evacuation arrangement. A further cause of delay can result from the hesitation experienced by untrained individuals at the moment of entry into and evacuation chute. In order to minimize this delay, it is desirable to provide an entry arrangement which does not commence with a vertical drop. Thus conventional chute arrangements may be modified to provide a non-vertical region at the upper end of the chute.
It is further desirable to provide a lightweight deployment structure for a chute arrangement that achieves a portion of its structural integrity and rigidity from the airframe of the aircraft, thus minimizing the weight and bulk of the structural elements of the device.
It is an object of the present invention to provide a passenger evacuation arrangement for emergency use in aircraft, and in particular for evacuating passengers from an upper deck or decks of a multi-deck aircraft. The invention may however be used in connection with other types of aircraft. It is a further object to provide an emergency evacuation arrangement for aircraft passengers, which is relatively light weight and compact when stowed and which safely, rapidly and effectively evacuates passengers to ground level. It is a further object to provide an arrangement consisting of a marine-type evacuation chute, and a frame for suspending the chute overboard of an aircraft in a vertical orientation, wherein the frame is relatively compact when in a stowed position. Conveniently, the frame may be stowed within any convenient location within the aircraft in a region within the vicinity of an escape hatch and is at least partly supported when in use by the aircraft frame.
In one aspect, the invention comprises an aircraft emergency passenger evacuation chute arrangement for discharging passengers from a hatch of an aircraft, comprising:
an elongate flexible tubular chute for conveying descending passengers when said chute is vertically suspended;
a carrier structure for stowing said chute within a folded or bunched stowage position, optionally including a chute support within said structure for supporting said chute wherein said chute support is separable from said carrier structure;
a chute suspension frame is associated with said carrier structure and engaged to an upper end of said chute. The frame is moveable between a stowed position substantially adjacent to or enclosed within the carrier structure, and a deployment position wherein the frame extends outwardly away from the carrier structure to displace a portion of the frame outwardly from the aircraft for the suspension of the chute from the frame portion;
means for removing said chute from said carrier structure; and
means for displacing said carrier structure from a stowage position inboard of said aircraft and spaced apart from said hatch, to a deployment position abutting the shell of said aircraft at said hatch.
Preferably, the suspension frame is longitudinally extensible and more preferably telescopic, for movement between a collapsed, stowed position associated with said carrier structure, to an extended deployment position extending outwardly from said housing.
Conveniently, the suspension frame is pivotally mounted at the base thereof to said carrier structure, preferably at the rear of the structure, for movement between a stowage position within or adjacent to said housing, to a deployment position wherein said support frame angles upwardly and outwardly relative to said aircraft.
The invention conveniently further comprises a pivotal mounting for the chute support. The pivotable mount, within the carrier structure, permits the support to rotate between a first position wherein the chute is enclosed within the said carrier structure, to a second, deployment position wherein the support angles downwardly and outwardly relative to the aircraft by an angle sufficient to carry the chute by force of gravity outwardly from said the housing.
Preferably the invention further comprises a chute housing for containing the chute. The housing is openable to release the chute therefrom upon deployment, the housing is releasably positioned within the carrier structure, and optionally carried on the chute support.
Conveniently, the housing comprises a base and cover frictionally engaged together and adapted to separate upon suspension of the chute from the suspension frame.
Conveniently, the chute is enclosed within an carrier structure defined by a base supporting the chute. The base is carried by the support and moveable relative thereto for deployment relative to the housing upon tilting of the support by a predetermined degree.
In a further aspect, the invention comprises a deployment arrangement for stowing and deploying a flexible chute, comprising the elements of the deployment structures characterized above.
In a further aspect, the invention comprises a method of deploying a chute from an aircraft, characterized by the steps of:
providing an elongate flexible tubular chute, a carrier structure for stowing the chute within a folded or bunched stowage position, a suspension frame associated with the carrier structure and engaged to an upper end of the chute, with the frame being pivotally mounted to the carrier structure;
displacing the carrier structure within the aircraft, from a stowage position in board of the aircraft and spaced apart from the hatch, to a deployment position abutting the shell of the aircraft at the hatch;
pivoting the suspension frame to a position whereby the suspension frame extends outwardly from the aircraft;
fastening the carrier structure to the aircraft frame at the deployment position, whereby the structural rigidity of the suspension frame is enhanced;
removing the chute from the carrier structure whereby the chute is suspended in a generally vertical position from the suspension frame.
Conveniently, the suspension frame is longitudinally extendable, and is extended longitudinally to form the deployment position. Further the suspension frame is conveniently pivoted from a stowage position substantially inboard of the carrier structure, to a deployment position where in the frame extends outwardly and upwardly relative to the aircraft.
In a further aspect, the invention comprises an aircraft emergency evacuation arrangement comprising a flexible evacuation chute, as characterized above, which extends but part way down to ground level when suspended from an aircraft. The lower end of the chute mates with an inflatable slide which when inflated carrier passengers from the lower end of the chute to ground level. A deployment structure suspends the chute and slide overboard of the aircraft in a deployment position, and carries the chute and slide inboard in a collapsed, storage position. The lower slide portion comprises a generally conventional aircraft emergency slide, including gas canisters for self-inflation upon deployment. The chute and slide are deposited directly on the slide for an uninterrupted journey.
The chute/slide combination permits the use of a shorter chute, with its attendant advantages of confronting passengers with a less of an intimidating vertical drop.
In a further aspect, a relatively short entry slide may be provided, in order to further ease fears of passengers. In this aspect, a self-inflating slide is mated to the upper end of the chute, whereby passengers may enter the chute via the entry slide. This permits passengers to enter the evacuation arrangement without being initially presented with the prospect of a vertical drop. Passengers will be less inclined to hesitate before entering the arrangement, this speeding up the evacuation process.
As used herein in reference to the chute deployment structure, the directional references xe2x80x9cfrontxe2x80x9d and xe2x80x9crearxe2x80x9d refer to the directions facing the aircraft shell and aircraft interior, respectively, along an axis transverse to the elongate axis of the aircraft.